1. Field of the Invention
The present invention relates to electronic components and, more particularly, to an electronic component including inner electrodes and outer electrodes including silver (Ag).
2. Description of the Related Art
Many electronic components, such as ceramic electronic components, are mounted on a wiring board installed in an electronic device. Although solder including lead (Pb) is generally used in the mounting of such electronic components on a wiring board in related art, an attempt to mount electronic components without using Pb is presently being pursued in order to reduce environmental loads.
For example, methods of mounting electronic components using conductive adhesive in which conductive fine particles, such as metallic filler, are added to thermosetting resin, such as thermosetting epoxy resin, or Pb-free solder are commonly used in order to mount the electronic components without using Pb. Various electronic components to which the above methods are preferably applicable are disclosed in, for example, Japanese Unexamined Patent Application Publication No. 2002-158137 and Japanese Unexamined Patent Application Publication No. 2002-203737.
As an electronic component that can be preferably mounted using Pb-free solder, Japanese Unexamined Patent Application Publication No. 2002-158137 discloses a multilayer ceramic electronic component in which outer electrodes are formed at both ends of a multilayer ceramic body including inner electrodes made of nickel (Ni) or a Ni alloy. In the multilayer ceramic electronic component, each outer electrode is a multilayer body in which base electrode layers primarily including copper (Cu) or a Cu alloy and outermost electrode layers primarily including Ag or an Ag alloy are laminated.
The electronic component using the electrode layers including Ag as the outermost electrode layers in the outer electrodes, as the one disclosed in Japanese Unexamined Patent Application Publication No. 2002-158137, is also preferably mounted using conductive adhesive. The use of the electrode layers including Ag as the outermost electrode layers in the outer electrodes allows the affinity between the outer electrodes and the conducive adhesive to be improved, thus increasing the mounting strength of the electronic component.
However, short circuit failure between the outer electrodes can be caused due to migration of Ag in the multilayer ceramic electronic component disclosed in Japanese Unexamined Patent Application Publication No. 2002-158137. In particular, when the multilayer ceramic electronic component disclosed in Japanese Unexamined Patent Application Publication No. 2002-158137 is used in a high temperature atmosphere of, for example, about 150° C. or greater, as in a case in which the multilayer ceramic electronic component is used in or near an engine control unit (ECU) in an automobile, the short circuit failure due to the migration of Ag is likely to occur.